Until recently, most of the industrial oxy-cutting and/or heating operations employed acetylene as fuel gas. Acetylene presented favorable cutting and heating characteristics because it has a high concentration of heat, temperature and flame emissivity, as well as a reduced consumption of oxygen necessary to the flame. Consequently, it provides a desirable technical performance when compared to the other available fuel gases.
However, despite proven technical advantages, the technologies for producing acetylene have not developed so much as to permit or provide a significant cost reduction for the use thereof. Thus, because acetylene is one of the most expensive gases among the gases available in the marketplace due to its high production cost which involves, among other factors, the manufacture of calcium carbide as the raw material for the acetylene, the operations of preparing and introducing the porous mass into the cylinders, the addition of acetone and filling the cylinders renders acetylene little economic competitiveness as compared to other fuel gases. In view of this, the consumers of fuel gases for oxy-cutting and heating operations are searching for a reduction in their operational costs through energetic alternatives which have a more competitive pricing than that of acetylene.
The production cost of the applications involving fuel gases is directly related to the characteristics of the oxygen consumption requirement of the fuel gas to produce the flame. Acetylene has been keeping competitive, although its prices are higher than the other fuel gas alternatives, since it requires a lower oxygen volume. The oxygen costs are, therefore, determinant in order that the acetylene be competitive with the other alternate fuel gases. The continuous development of new oxygen producing technologies is significantly reducing the producing costs of these gases, providing a reduction in the average prices thereof. In view of this, other fuel gas alternates have become viable, as their producing costs are lower than that of the acetylene, although these fuel gases need a greater oxygen amount for the flame.
In view of the high costs of the applications employing acetylene, fuel gas alternates are being investigated, the prices of which are lower than that of acetylene. Thus, GLP, propylene and additivated GLP, among others, are being currently utilized by the industry.
Although requiring a greater oxygen volume for carrying out the combustion, GLP has been employed in industrial applications, favored by the reduction in the average oxygen price and its low price.
Propylene, like GLP, is a petroleum based liquefied gas and another alternative to the use of acetylene in industrial gas processes. It is relatively less expensive as compared to acetylene and, although propylene requires a higher oxygen consumption to produce the flame, it is also favored by the current reduction in the average oxygen price in the marketplace. Although propylene has a price greater than that of GLP, there is a great difference between the ratios of consumption of oxygen required by GLP and by propylene, thus allowing the achievement of a lower final cost on behalf of propylene in industrial processes.
Additivated GLP is a recent alternative obtained by means of the GLP chemical additivation, which enhances the combustion characteristics of this gas, matching it with propylene, without, however, causing a significant increase in the production cost and, consequently, in the final price of the fuel.
In addition to price, another advantage of the liquefied gases over the acetylene is the form for storing the product. While acetylene is conditioned in cylinders and dissolved in adequate solvent, the liquefied gases are stored in the liquid form, in cylinders or tanks of high capacity, bringing about a lower conveying cost and higher handling safety.
Although these alternate fuel gases are being employed in place of acetylene, they do not allow for a completely satisfactory substitution of the acetylene, due to the low productivity of these gases, as they do not provide cutting velocities equal to or greater than those obtained by the acetylene, since they present an oxygen consumption superior to that presented by the acetylene.
Therefore, it is an objective of the present invention to present an additivated fuel gas for oxy-cutting and/or heating applications, which is able to provide a higher productivity, that is, a higher cutting velocity and a lower oxygen and fuel gas consumption.
It is another objective of the present invention to present an additivated fuel gas for oxy-cutting and/or heating applications having a low cost of production.
These and other objectives of the present invention are achieved by the additivation of propylene with a chemical product having as basic constituents aromatic compounds, paraffins and naphthenic compounds, at such concentrations that it provides a cutting and heating productivity superior to the fuel gases currently employed, providing higher cutting velocities, a lower oxygen and fuel gas consumption, as well as having a low cost of production.